The present invention relates to an apparatus and method for generating landing fee and other airport service bills automatically. In particular, the present invention is directed toward a system and method for automatically detecting aircraft N-number from air traffic control voice data using a voice recognition system, and automatically billing aircraft owners for landing fees based upon this voice recognition as well as upon aircraft position detection.
The issued U.S. patents and pending applications incorporated by reference above disclose techniques for detecting aircraft position by receiving aircraft radio signals (e.g., mode-S, mode-A, or mode-C transponder or the like) at a multitude of local receivers and detecting aircraft position based upon Time Difference of Arrival (TDOA) or other multilateration or other techniques. Thus, systems are known (at least to the present inventors) for detecting aircraft position using various techniques.
Airports collect revenues in a number of ways. In addition to airport ticket taxes, concession fees, hangar rent, and the like, airports collect landing fees from each aircraft landing at a particular airport. For larger airports handing mostly scheduled commercial (airline) traffic, calculating these landing fees and billing for them is a relatively simple process. Airlines run with preset schedules available to the airport operator, and moreover, detailed landing logs are kept as part of Air Traffic Control records.
However, for many smaller and midsize airports, monitoring and collecting landing fees can be quite difficult. General Aviation, Tour, Charter, Flight Instruction, and Regional Airliner aircraft may arrive and depart at unscheduled times. Moreover, aircraft which are not based at the airport or which do not regularly fly to the airport may land perhaps once. Without detailed aircraft ownership records and landing records, it may be difficult to account for, bill for, and collect landing fees.
The problem of collecting landing fees is not trivial. In one airport utilizing the system of the present invention, collected landing fees nearly doubled after installation. As such, it may be typical that as much as half of all landing fees in small to medium sized airports are never logged, billed, or collected.
In a small or midsize airport, the amount of staff available for landing fee collection may be limited or non-existent. Air Traffic Control personnel (e.g., tower personnel) may be the only method of logging and collecting landing fees. Since the other personnel are more concerned with safe airport operation than billing, landings may fail to be properly logged, particularly during busy periods (e.g., more than one plane in landing pattern, or the like).
As noted above, techniques exist for detecting the presence or location of an aircraft using radio receivers to monitor transponder frequencies (e.g., Mode-C and/or Mode-S transponders) Most general aviation aircraft are equipped with such transponders. Moreover, even if not equipped with a transponder, a general aviation aircraft will most likely be equipped with a radio for verbal communication with the tower. Thus, most general aviation aircraft will emit some type of radio signal when in the vicinity of the airport.
The present invention monitors aircraft position or vicinity by receiving aircraft radio signals. Position can be determined by measuring Time Difference of Arrival (TDOA) or in the alterative, vicinity can be measured simply by intensity of radio signal. When the position of an aircraft is determined to be within range of the airport, and the aircraft descends to the level and location of the airport, the system determines that a landing has occurred.
If the signal monitored is a Mode-S signal, aircraft registration (xe2x80x9cNxe2x80x9d number) may be decoded from the Mode-S signal using a predetermined algorithm. However, many general aviation (GA) aircraft still utilize mode C or mode A transponders which do not provide N-number information and cannot be decoded to provide N-number information.
Thus, the system also monitors the Air Traffic Control (ATC) or tower signals for audio signals from the tower controller audio signals. In the preferred embodiment, the system can tap directly into the tower radio to receive a high quality xe2x80x9ccleanxe2x80x9d audio signal without interference. In an alternative embodiment, the system may monitor tower frequencies to capture tower audio signal data.
A voice recognition system receives tower voice signals and outputs text data. In particular, the system monitors tower voice signals for recitation of aircraft registration number (xe2x80x9cNxe2x80x9d number) by the tower controller. The system then matches N number with the aircraft landing to generate a billing event.
From an aircraft owner""s database (e.g., FAA records or the like), the system can generate a complete landing fee billing statement, complete with aircraft owner address, ready to be mailed or given to the aircraft owner. The billing system may also be provided with, or interface with, other known billing features (e.g., Accounts Receivable statements and other accounting features).
The system may be provided with fail-safe features to prevent multiple billing for the same landing event. For example, the number of billing events for a given N-number aircraft may be limited per unit time to prevent double-billing for the same landing. Thus, for example, and aircraft may be limited to one landing bill per half hour or other increment of time. If an aircraft has to abort a landing and go around to land again, the system will recognize such an event and may bill for only one landing.
For special aircraft operations, such as flight schools, skydiving services, crop dusting, air taxi, sight seeing tours, and the like, where multiple take-offs and landings may occur within a certain time period, a pre-arrange flat rate may be negotiated, or the system may be programmed to log predetermined N-number aircraft with a different frequency than general aircraft.